From 5263736754b8a1d4bca3f157b1af931b638e37e3 Mon Sep 17 00:00:00 2001 From: Jeremy Lilly Date: Thu, 19 Oct 2023 10:28:30 -0700 Subject: [PATCH 1/4] Implement FB_LTS local time-stepping scheme for single layer MPAS-O --- components/mpas-ocean/src/Registry.xml | 16 +- .../mpas-ocean/src/mode_forward/Makefile | 9 +- .../mode_forward/mpas_ocn_time_integration.F | 10 +- .../mpas_ocn_time_integration_fblts.F | 1963 +++++++++++++++++ .../src/shared/mpas_ocn_diagnostics.F | 6 +- .../mpas-ocean/src/shared/mpas_ocn_tendency.F | 4 +- .../src/shared/mpas_ocn_vel_hadv_coriolis.F | 4 + .../src/shared/mpas_ocn_vel_pressure_grad.F | 3 +- .../src/shared/mpas_ocn_vel_tidal_potential.F | 3 +- 9 files changed, 2010 insertions(+), 8 deletions(-) create mode 100644 components/mpas-ocean/src/mode_forward/mpas_ocn_time_integration_fblts.F diff --git a/components/mpas-ocean/src/Registry.xml b/components/mpas-ocean/src/Registry.xml index f8b56c083d44..68406ed98262 100644 --- a/components/mpas-ocean/src/Registry.xml +++ b/components/mpas-ocean/src/Registry.xml @@ -202,7 +202,7 @@ /> + + + + + \brief MPAS barotropic ocean LTS Time integration scheme +!> \author Jeremy Lilly +!> \date October 2023 +!> \details +!> This module contains the FB_LTS init routine and the FB_LTS +!> barotropic ocean time integration scheme with splitting +!> on the fast and slow tendency terms. +! +!----------------------------------------------------------------------- + +module ocn_time_integration_fblts + + use mpas_pool_routines + use mpas_dmpar + use mpas_threading + use mpas_vector_reconstruction + use mpas_timer + + use ocn_tendency + use ocn_diagnostics + use ocn_mesh + use ocn_vmix + use ocn_config + use ocn_time_average_coupled + + implicit none + private + save + + !-------------------------------------------------------------------- + ! + ! Public member functions + ! + !-------------------------------------------------------------------- + public :: ocn_time_integrator_fblts, & + ocn_time_integration_fblts_init + + contains + + +!||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| +! +! ocn_time_integrator_fblts +! +!> \brief MPAS barotropic ocean FB_LTS time integration scheme +!> \author Jeremy Lilly +!> \date October 2023 +!> \details +!> This routine integrates one timestep (dt) using an FB_LTS time +!> integrator with a splitting of the fast and slow tendency terms +! +!----------------------------------------------------------------------- + + subroutine ocn_time_integrator_fblts(domain, dt)!{{{ + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! Advance model state forward in time by the specified time step + ! using a local time stepping scheme with splitting of the fast and + ! slow tendencies + ! + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + implicit none + + !----------------------------------------------------------------- + ! Input variables + !----------------------------------------------------------------- + + real (kind=RKIND), intent(in) :: & + dt !< [in] time step (sec) to move forward + + !----------------------------------------------------------------- + ! Input/output variables + !----------------------------------------------------------------- + + type (domain_type), intent(inout) :: & + domain !< [inout] model state to advance forward + + !----------------------------------------------------------------- + ! Local variables + !----------------------------------------------------------------- + + integer :: & + iCell, iEdge, iRegion, k, ic, ie, im, & ! iterators + M, & ! M = dtCoarse / dtFine + nRegions ! number of interface regions (two) + + type (block_type), pointer :: & + block ! structure with subdomain data + + type (mpas_pool_type), pointer :: & + tendPool, & ! structure holding tendencies + statePool, & ! structure holding state variables + meshPool, & ! structure holding mesh variables + verticalMeshPool, & ! structure holding mesh variables + forcingPool, & ! structure holding forcing variables + scratchPool, & ! structure holding temporary variables + tracersPool ! structure holding tracers variables + + ! LTS Pools + type (mpas_pool_type), pointer :: & + LTSPool, & ! structure holding LTS variables + tendSlowPool, & ! structure holding the slow tendency variables + tendSum3rdPool, & ! structure holding one of the correction terms for the interface + prevTendSlowPool, nextTendSlowPool, & ! structures containing intermediate data + prevTendSum3rdPool, nextTendSum3rdPool ! structures containing intermediate data + + ! Tend Array Pointers + real (kind=RKIND), dimension(:,:), pointer :: & + normalVelocityTend, & ! normal velocity fast tendency + layerThicknessTend, & ! layer thickness tendency + normalVelocityTendSlow, & ! normal velocity slow tendency + normalVelocityTendSum3rd, & ! one of the normal velocity correction terms for the interface + layerThicknessTendSum3rd ! one of the layer thickness correction terms for the interface + + ! State Array Pointers + real (kind=RKIND), dimension(:,:), pointer :: & + normalVelocityCur, & ! normal velocity at time n + normalVelocityNew, & ! normal velocity at time n+1 + normalVelocityFirstStage, & ! normal velocity at first stage of LTS + normalVelocitySecondStage, & ! normal velocity at second stage of LTS + normalVelocityForTend, & ! extra variable to store averages of data for tends calculations + layerThicknessCur, & ! layer thickness at time n + layerThicknessNew, & ! layer thickness at time n+1 + layerThicknessFirstStage, & ! layer thickness at first stage of LTS + layerThicknessSecondStage, & ! layer thickness at second stage of LTS + layerThicknessForTend ! extra variable to store averages of data for tends calculations + + ! Local pointer for ssh + real (kind=RKIND), dimension(:), pointer :: & + ssh + + ! LTS objects + real (kind=RKIND) :: & + dtFine ! fine dt, defined as dt / M + integer, dimension(:,:), pointer :: & + nCellsInLTSRegion, & ! number of cells in a given LTS region + nEdgesInLTSRegion ! number of edges in a given LTS region + integer, dimension(:,:,:), pointer :: & + cellsInLTSRegion, & ! list of cells in a given LTS region + edgesInLTSRegion ! list of edges in a given LTS region + real (kind=RKIND) :: & + weight1st, weight2nd ! coefficients for each RK stage + real (kind=RKIND) :: & + weightTendSum3rd ! coefficients for the interface correction + + integer err + err = 0 + + !----------------------------------------------------------------- + ! Begin routine + !----------------------------------------------------------------- + + if (.not. config_disable_tr_all_tend) then + call mpas_log_write("ERROR: tracers are not currently implemented for local time-stepping") + call mpas_log_write("config_disable_tr_all_tend should be true in the namelist file") + call abort + end if + + + call mpas_timer_start("FB_LTS time-step prep") + + ! LTS parameters + M = config_dt_scaling_LTS + nRegions = 2 + dtFine = dt / M + + ! Weights for RK stages, weight for third stage is 1 + weight1st = 1.0_RKIND / 3.0_RKIND + weight2nd = 1.0_RKIND / 2.0_RKIND + + block => domain % blocklist + + ! Retrieve model state, pools + call mpas_pool_get_subpool(block%structs, 'mesh', meshPool) + call mpas_pool_get_subpool(block%structs, 'verticalMesh', verticalMeshPool) + call mpas_pool_get_subpool(block%structs, 'state', statePool) + call mpas_pool_get_subpool(block%structs, 'forcing', forcingPool) + call mpas_pool_get_subpool(block%structs, 'LTS', LTSPool) + call mpas_pool_get_subpool(block%structs, 'tend', tendPool) + call mpas_pool_get_subpool(block%structs, 'scratch', scratchPool) + call mpas_pool_get_subpool(statePool, 'tracers', tracersPool) + + ! Retrieve state variables at necessary time levels + call mpas_pool_get_array(statePool, 'normalVelocity', & + normalVelocityCur, 1) + call mpas_pool_get_array(statePool, 'normalVelocity', & + normalVelocityNew, 2) + call mpas_pool_get_array(statePool, 'normalVelocity', & + normalVelocityFirstStage, 3) + call mpas_pool_get_array(statePool, 'normalVelocity', & + normalVelocitySecondStage, 4) + call mpas_pool_get_array(statePool, 'normalVelocity', & + normalVelocityForTend, 5) + call mpas_pool_get_array(statePool, 'layerThickness', & + layerThicknessCur, 1) + call mpas_pool_get_array(statePool, 'layerThickness', & + layerThicknessNew, 2) + call mpas_pool_get_array(statePool, 'layerThickness', & + layerThicknessFirstStage, 3) + call mpas_pool_get_array(statePool, 'layerThickness', & + layerThicknessSecondStage, 4) + call mpas_pool_get_array(statePool, 'layerThickness', & + layerThicknessForTend, 5) + + ! Retrieve tendency variables + call mpas_pool_get_array(tendPool, 'normalVelocity', normalVelocityTend) + call mpas_pool_get_array(tendPool, 'layerThickness', layerThicknessTend) + + ! Retrieve LTS arrays + call mpas_pool_get_array(LTSPool, 'cellsInLTSRegion', cellsInLTSRegion) + call mpas_pool_get_array(LTSPool, 'nCellsInLTSRegion', nCellsInLTSRegion) + call mpas_pool_get_array(LTSPool, 'edgesInLTSRegion', edgesInLTSRegion) + call mpas_pool_get_array(LTSPool, 'nEdgesInLTSRegion', nEdgesInLTSRegion) + + ! Create and retrieve additional pools for LTS + call mpas_pool_create_pool(tendSum3rdPool) + call mpas_pool_clone_pool(tendPool, tendSum3rdPool, 1) + call mpas_pool_create_pool(tendSlowPool) + call mpas_pool_clone_pool(tendPool, tendSlowPool, 1) + + call mpas_pool_add_subpool(block % structs, 'tend_sum_3rd', tendSum3rdPool) + call mpas_pool_add_subpool(block % structs, 'tend_slow', tendSlowPool) + + call mpas_pool_get_array(tendSlowPool, 'normalVelocity', & + normalVelocityTendSlow) + call mpas_pool_get_array(tendSum3rdPool, 'normalVelocity', & + normalVelocityTendSum3rd) + call mpas_pool_get_array(tendSum3rdPool, 'layerThickness', & + layerThicknessTendSum3rd) + + ! Init variables + do iEdge = 1, nEdgesAll ! do we need this? + do k = 1, maxLevelEdgeTop(iEdge) + normalVelocityNew(k, iEdge) = normalVelocityCur(k, iEdge) + normalVelocityFirstStage(k, iEdge) = normalVelocityCur(k, iEdge) + normalVelocitySecondStage(k, iEdge) = normalVelocityCur(k, iEdge) + end do + end do + + do iCell = 1, nCellsAll ! do we need this? + do k = 1, maxLevelCell(iCell) + layerThicknessNew(k, iCell) = layerThicknessCur(k, iCell) + layerThicknessFirstStage(k, iCell) = layerThicknessCur(k, iCell) + layerThicknessSecondStage(k, iCell) = layerThicknessCur(k, iCell) + end do + end do + + normalVelocityTendSum3rd(:,:) = 0.0_RKIND + layerThicknessTendSum3rd(:,:) = 0.0_RKIND + + if (associated(block % prev)) then + call mpas_pool_get_subpool(block % prev % structs, 'tend_sum_3rd', tendSum3rdPool) + call mpas_pool_get_subpool(block % prev % structs, 'tend_slow', tendSlowPool) + else + nullify(prevTendSum3rdPool) + nullify(prevTendSlowPool) + end if + + if (associated(block % next)) then + call mpas_pool_get_subpool(block % next % structs, 'tend_sum_3rd', nextTendSum3rdPool) + call mpas_pool_get_subpool(block % next % structs, 'tend_slow', nextTendSlowPool) + else + nullify(nextTendSum3rdPool) + nullify(nextTendSlowPool) + end if + + call mpas_pool_get_subpool(block % structs, 'tend_sum_3rd', tendSum3rdPool) + call mpas_pool_get_subpool(block % structs, 'tend_slow', tendSlowPool) + + if (associated(prevTendSum3rdPool) .and. associated(nextTendSum3rdPool)) then + call mpas_pool_link_pools(tendSum3rdPool, prevTendSum3rdPool, nextTendSum3rdPool) + else if (associated(prevTendSum3rdPool)) then + call mpas_pool_link_pools(tendSum3rdPool, prevTendSum3rdPool) + else if (associated(nextTendSum3rdPool)) then + call mpas_pool_link_pools(tendSum3rdPool,nextPool=nextTendSum3rdPool) + else + call mpas_pool_link_pools(tendSum3rdPool) + end if + + if (associated(prevTendSlowPool) .and. associated(nextTendSlowPool)) then + call mpas_pool_link_pools(tendSlowPool, prevTendSlowPool, nextTendSlowPool) + else if (associated(prevTendSlowPool)) then + call mpas_pool_link_pools(tendSlowPool, prevTendSlowPool) + else if (associated(nextTendSlowPool)) then + call mpas_pool_link_pools(tendSlowPool,nextPool=nextTendSlowPool) + else + call mpas_pool_link_pools(tendSlowPool) + end if + + call mpas_pool_link_parinfo(block, tendSum3rdPool) + call mpas_pool_link_parinfo(block, tendSlowPool) + + call mpas_timer_stop("FB_LTS time-step prep") + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! + ! BEGIN FB_LTS SCHEME + ! + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + call mpas_timer_start("FB_LTS main loop") + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Slow tendency calculation + ! Calculate the slow tendencies on all LTS regions (only the + ! momentum equation contains slow terms) + call mpas_timer_start("FB_LTS compute slow tendencies") + + call ocn_tend_vel(domain, tendSlowPool, statePool, forcingPool, 1, & + domain % dminfo, dt) + + call mpas_timer_stop("FB_LTS compute slow tendencies") + ! END: Slow tendency calculation + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN COARSE ADVANCEMENT + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Thickness stage 1 + ! Compute the first stage of the thickness on fine*, interface 1, + ! interface 2, and coarse + + ! Compute fast tendencies for thickness + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast thickness tendencies") + + call ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocityCur, layerThicknessCur, & + 0, 1, 1, 1, 1) + + call mpas_timer_stop("FB_LTS compute fast thickness tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance thickness solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance thickness solution") + + ! Interface layers + do iRegion = 1,nRegions + do ic = 1, nCellsInLTSRegion(iRegion,2) + iCell = cellsInLTSRegion(iRegion,2,ic) + layerThicknessFirstStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight1st * dt * layerThicknessTend(:,iCell) + end do + end do + ! Coarse + do ic = 1, nCellsInLTSRegion(2,1) + iCell = cellsInLTSRegion(2,1,ic) + layerThicknessFirstStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight1st * dt * layerThicknessTend(:,iCell) + end do + ! Fine layers close to interface layers + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessFirstStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight1st * dt * layerThicknessTend(:,iCell) + end do + + call mpas_timer_stop("FB_LTS advance thickness solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Thickness stage 1 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Normal velocity stage 1 + ! Compute the first stage of the normal velocity on fine*, + ! interface 1, interface 2, and coarse + + ! Perform forward-backward average of thickness for stage one of + ! FB-RK(3,2): + ! h = weight1*stage1 + (1-weight1)*current + layerThicknessForTend(:,:) = config_fb_weight_1 * layerThicknessFirstStage(:,:) & + + (1.0_RKIND - config_fb_weight_1) * layerThicknessCur(:,:) + + ! Halo update before tend calculation + ! Might be able to remove this? + call mpas_timer_start("FB_LTS prognostic halo update") + + ! Don't need to update normalVelocityCur, already updated + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for normal velocity + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast velocity tendencies") + + call ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocityCur, layerThicknessForTend, & + 0, 1, 1, 1, 1) + + normalVelocityTend(:,:) = normalVelocityTend(:,:) & + + normalVelocityTendSlow(:,:) + + call mpas_timer_stop("FB_LTS compute fast velocity tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance normal velocity solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance velocity solution") + + ! Interface regions + do iRegion = 1,nRegions + do ie = 1, nEdgesInLTSRegion(iRegion,2) + iEdge = edgesInLTSRegion(iRegion,2,ie) + normalVelocityFirstStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight1st * dt * normalVelocityTend(:,iEdge) + end do + end do + ! Coarse + do ie = 1, nEdgesInLTSRegion(2,1) + iEdge = edgesInLTSRegion(2,1,ie) + normalVelocityFirstStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight1st * dt * normalVelocityTend(:,iEdge) + end do + ! Fine layers close to interface layers + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + normalVelocityFirstStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight1st * dt * normalVelocityTend(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS advance velocity solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Normal velocity stage 1 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Thickness stage 2 + ! Compute the second stage of the thickness on fine*, interface 1, + ! interface 2, and coarse + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=3) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=3) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for thickness + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast thickness tendencies") + + call ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocityFirstStage, layerThicknessFirstStage, & + 0, 1, 1, 1, 1) + + call mpas_timer_stop("FB_LTS compute fast thickness tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance thickness solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance thickness solution") + + ! Interface layers + do iRegion = 1,nRegions + do ic = 1, nCellsInLTSRegion(iRegion,2) + iCell = cellsInLTSRegion(iRegion,2,ic) + layerThicknessSecondStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight2nd * dt * layerThicknessTend(:,iCell) + end do + end do + ! Coarse + do ic = 1, nCellsInLTSRegion(2,1) + iCell = cellsInLTSRegion(2,1,ic) + layerThicknessSecondStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight2nd * dt * layerThicknessTend(:,iCell) + end do + ! Fine layers close to interface layers + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessSecondStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight2nd * dt * layerThicknessTend(:,iCell) + end do + + call mpas_timer_stop("FB_LTS advance thickness solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Thickness stage 2 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Normal velocity stage 2 + ! Compute the second stage of the normal velocity on fine*, + ! interface 1, interface 2, and coarse + + ! Perform forward-backward average of thickness for stage two of + ! FB-RK(3,2): + ! h = weight2*stage2 + (1-weight2)*current + layerThicknessForTend(:,:) = config_fb_weight_2 * layerThicknessSecondStage(:,:) & + + (1.0_RKIND - config_fb_weight_2) * layerThicknessCur(:,:) + + ! Halo update before tend calculation + ! Might be able to remove this? + call mpas_timer_start("FB_LTS prognostic halo update") + + ! Don't need to update normalVelocityFirstStage, previously updated + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for normal velocity + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast velocity tendencies") + + call ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocityFirstStage, layerThicknessForTend, & + 0, 1, 1, 1, 1) + + normalVelocityTend(:,:) = normalVelocityTend(:,:) & + + normalVelocityTendSlow(:,:) + + call mpas_timer_stop("FB_LTS compute fast velocity tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance normal velocity solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance velocity solution") + + ! Interface regions + do iRegion = 1,nRegions + do ie = 1, nEdgesInLTSRegion(iRegion,2) + iEdge = edgesInLTSRegion(iRegion,2,ie) + normalVelocitySecondStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight2nd * dt * normalVelocityTend(:,iEdge) + end do + end do + ! Coarse + do ie = 1, nEdgesInLTSRegion(2,1) + iEdge = edgesInLTSRegion(2,1,ie) + normalVelocitySecondStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight2nd * dt * normalVelocityTend(:,iEdge) + end do + ! Fine layers close to interface layers + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + normalVelocitySecondStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight2nd * dt * normalVelocityTend(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS advance velocity solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Normal velocity stage 2 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Thickness stage 3 + ! Compute the third stage of the thickness on fine*, interface 1, + ! interface 2, and coarse + + ! Halo update before tends calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=4) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=4) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for thickness + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast thickness tendencies") + + call ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocitySecondStage, layerThicknessSecondStage, & + 0, 1, 1, 1, 1) + + call mpas_timer_stop("FB_LTS compute fast thickness tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance thickness solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance thickness solution") + + ! Interface layers + do iRegion = 1,nRegions + do ic = 1, nCellsInLTSRegion(iRegion,2) + iCell = cellsInLTSRegion(iRegion,2,ic) + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) & + + dt * layerThicknessTend(:,iCell) + end do + end do + ! Coarse + do ic = 1, nCellsInLTSRegion(2,1) + iCell = cellsInLTSRegion(2,1,ic) + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) & + + dt * layerThicknessTend(:,iCell) + end do + ! Fine layers close to interface layers + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) & + + dt * layerThicknessTend(:,iCell) + end do + + call mpas_timer_stop("FB_LTS advance thickness solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Thickness stage 3 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Normal velocity stage 3 + ! Compute the third stage of the normal velocity on, interface 1, + ! and coarse + + ! Perform forward-backward average of thickness for stage three of + ! FB-RK(3,2): + ! h = weight3*new + (1-2*weight3)*secondStage + weight3*current + layerThicknessForTend(:,:) = config_fb_weight_3 * layerThicknessNew(:,:) & + + (1.0_RKIND - 2.0_RKIND*config_fb_weight_3) * layerThicknessSecondStage(:,:) & + + config_fb_weight_3 * layerThicknessCur(:,:) + + ! Halo update before tend calculation + ! Might be able to remove this? + call mpas_timer_start("FB_LTS prognostic halo update") + + ! Don't need to update normalVelocitySecondStage, previously updated + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for normal velocity + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast velocity tendencies") + + call ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocitySecondStage, layerThicknessForTend, & + 0, 0, 1, 0, 1) + + normalVelocityTend(:,:) = normalVelocityTend(:,:) & + + normalVelocityTendSlow(:,:) + + call mpas_timer_stop("FB_LTS compute fast velocity tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance normal velocity solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance velocity solution") + + ! Interface 1 + do ie = 1, nEdgesInLTSRegion(1,2) + iEdge = edgesInLTSRegion(1,2,ie) + normalVelocityNew(:,iEdge) = normalVelocityCur(:,iEdge) & + + dt * normalVelocityTend(:,iEdge) + end do + ! Coarse + do ie = 1, nEdgesInLTSRegion(2,1) + iEdge = edgesInLTSRegion(2,1,ie) + normalVelocityNew(:,iEdge) = normalVelocityCur(:,iEdge) & + + dt * normalVelocityTend(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS advance velocity solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Normal velocity stage 3 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! END COARSE ADVANCEMENT + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN FINE ADVANCEMENT + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + do im = 0, M-1 + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Thickness stage 1 + ! Compute the first stage of the thickness on fine + + ! Calculate predicted 'current' data at intermediate + ! time-level on interface 1: + ! u,h = (im/M)*new + (1- (im/M))*current + call mpas_timer_start('FB_LTS interface prediction') + + normalVelocityForTend(:,:) = normalVelocityCur(:,:) + do ie = 1, nEdgesInLTSRegion(1,2) + iEdge = edgesInLTSRegion(1,2,ie) + normalVelocityForTend(:,iEdge) = (REAL(im)/M) * normalVelocityNew(:,iEdge) & + + (1.0_RKIND - REAL(im)/M) * normalVelocityCur(:,iEdge) + end do + + layerThicknessForTend(:,:) = layerThicknessCur(:,:) + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + layerThicknessForTend(:,iCell) = (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND - REAL(im)/M) * layerThicknessCur(:,iCell) + end do + + call mpas_timer_stop('FB_LTS interface prediction') + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=5) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for thickness + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast thickness tendencies") + + call ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocityForTend, layerThicknessForTend, & + 1, 1, 0, 0, 0) + + call mpas_timer_stop("FB_LTS compute fast thickness tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance thickness solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance thickness solution") + + ! Fine cells adjacent to interface 1 + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessFirstStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight1st * dtFine * layerThicknessTend(:,iCell) + end do + ! Fine in the interior, away from interface 1 + do ic = 1, nCellsInLTSRegion(1,1) + iCell = cellsInLTSRegion(1,1,ic) + layerThicknessFirstStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight1st * dtFine * layerThicknessTend(:,iCell) + end do + + call mpas_timer_stop("FB_LTS advance thickness solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Thickness stage 1 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Normal velocity stage 1 + ! Compute the first stage of the normal velocity on fine + + ! Perform forward-backward average of thickness for stage one of + ! FB-RK(3,2): + ! h = weight1*stage1 + (1-weight1)*current + layerThicknessForTend(:,:) = config_fb_weight_1 * layerThicknessFirstStage(:,:) & + + (1.0_RKIND - config_fb_weight_1) * layerThicknessCur(:,:) + + ! Calculate predicted FB averaged thickness data at + ! intermediate time-level on interface 1: + ! h = weight1*'firstStage' + (1-weight1)*'current' + ! = weight1*( (im/M)*new + (1/M)*firstStage + (1-(im+1)/M)*current ) + ! + (1-weight1)*( (im/M)*new + (1-im/M)*current ) + call mpas_timer_start('FB_LTS interface prediction') + + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + layerThicknessForTend(:,iCell) = config_fb_weight_1 & + * ( (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND/M) * layerThicknessFirstStage(:,iCell) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * layerThicknessCur(:,iCell) ) & + + (1.0_RKIND - config_fb_weight_1) & + * ( (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND - REAL(im)/M) * layerThicknessCur(:,iCell) ) + end do + + call mpas_timer_stop('FB_LTS interface prediction') + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + ! Don't need to update normalVelocityForTend, previously updated + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for normal velocity + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast velocity tendencies") + + call ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocityForTend, layerThicknessForTend, & + 1, 1, 0, 0, 0) + + normalVelocityTend(:,:) = normalVelocityTend(:,:) & + + normalVelocityTendSlow(:,:) + + call mpas_timer_stop("FB_LTS compute fast velocity tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance normal velocity solution with first stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance velocity solution") + + ! Fine cells adjacent to interface 1 + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + normalVelocityFirstStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight1st * dtFine * normalVelocityTend(:,iEdge) + end do + ! Fine in the interior, away from interface 1 + do ie = 1, nEdgesInLTSRegion(1,1) + iEdge = edgesInLTSRegion(1,1,ie) + normalVelocityFirstStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight1st * dtFine * normalVelocityTend(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS advance velocity solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Normal velocity stage 1 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Thickness stage 2 + ! Compute the second stage of the thickness on fine + + ! Calculate predicted stage 1 data at intermediate + ! time-level on interface 1: + ! u,h = (im/M)*new + (1/M)*firstStage + (1-(im+1)/M)*current + call mpas_timer_start('FB_LTS interface prediction') + + normalVelocityForTend(:,:) = normalVelocityFirstStage(:,:) + do ie = 1, nEdgesInLTSRegion(1,2) + iEdge = edgesInLTSRegion(1,2,ie) + normalVelocityForTend(:,iEdge) = (REAL(im)/M) * normalVelocityNew(:,iEdge) & + + (1.0_RKIND/M) * normalVelocityFirstStage(:,iEdge) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * normalVelocityCur(:,iEdge) + end do + + layerThicknessForTend(:,:) = layerThicknessFirstStage(:,:) + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + layerThicknessForTend(:,iCell) = (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND/M) * layerThicknessFirstStage(:,iCell) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * layerThicknessCur(:,iCell) + end do + + call mpas_timer_stop('FB_LTS interface prediction') + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=5) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for thickness + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast thickness tendencies") + + call ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocityForTend, layerThicknessForTend, & + 1, 1, 0, 0, 0) + + call mpas_timer_stop("FB_LTS compute fast thickness tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance thickness solution with second stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance thickness solution") + + ! Fine cells adjacent to interface 1 + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessSecondStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight2nd * dtFine * layerThicknessTend(:,iCell) + end do + ! Fine in the interior, away from interface 1 + do ic = 1, nCellsInLTSRegion(1,1) + iCell = cellsInLTSRegion(1,1,ic) + layerThicknessSecondStage(:,iCell) = layerThicknessCur(:,iCell) & + + weight2nd * dtFine * layerThicknessTend(:,iCell) + end do + + call mpas_timer_stop("FB_LTS advance thickness solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Thickness stage 2 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Normal velocity stage 2 + ! Compute the second stage of the normal velocity on fine + + ! Perform forward-backward average of thickness for stage two of + ! FB-RK(3,2): + ! h = weight2*stage2 + (1-weight2)*current + layerThicknessForTend(:,:) = config_fb_weight_2 * layerThicknessSecondStage(:,:) & + + (1.0_RKIND - config_fb_weight_2) * layerThicknessCur(:,:) + + ! Calculate predicted FB averaged thickness data at + ! intermediate time-level on interface 1: + ! h = weight2*'secondStage' + (1-weight2)*'current' + ! = weight2*( (im/M)*new + (1/M)*secondStage + (1-(im+1)/M)*current ) + ! + (1-weight2)*( (im/M)*new + (1-im/M)*current ) + call mpas_timer_start('FB_LTS interface prediction') + + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + layerThicknessForTend(:,iCell) = config_fb_weight_2 & + * ( (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND/M) * layerThicknessSecondStage(:,iCell) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * layerThicknessCur(:,iCell) ) & + + (1.0_RKIND - config_fb_weight_2) & + * ( (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND - REAL(im)/M) * layerThicknessCur(:,iCell) ) + end do + + call mpas_timer_stop('FB_LTS interface prediction') + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + ! Don't need to update normalVelocityForTend, previously updated + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for normal velocity + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast velocity tendencies") + + call ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocityForTend, layerThicknessForTend, & + 1, 1, 0, 0, 0) + + normalVelocityTend(:,:) = normalVelocityTend(:,:) & + + normalVelocityTendSlow(:,:) + + call mpas_timer_stop("FB_LTS compute fast velocity tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance normal velocity solution with second stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance velocity solution") + + ! Fine cells adjacent to interface 1 + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + normalVelocitySecondStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight2nd * dtFine * normalVelocityTend(:,iEdge) + end do + ! Fine in the interior, away from interface 1 + do ie = 1, nEdgesInLTSRegion(1,1) + iEdge = edgesInLTSRegion(1,1,ie) + normalVelocitySecondStage(:,iEdge) = normalVelocityCur(:,iEdge) & + + weight2nd * dtFine * normalVelocityTend(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS advance velocity solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Normal velocity stage 2 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Thickness stage 3 + ! Compute the third stage of the thickness on fine and + ! increment the third stage interface correction terms + + ! Calculate predicted stage 2 data at intermediate + ! time-level on interface 1: + ! u,h = (im/M)*new + (1/M)*secondStage + (1-(im+1)/M)*current + call mpas_timer_start('FB_LTS interface prediction') + + normalVelocityForTend(:,:) = normalVelocitySecondStage(:,:) + do ie = 1, nEdgesInLTSRegion(1,2) + iEdge = edgesInLTSRegion(1,2,ie) + normalVelocityForTend(:,iEdge) = (REAL(im)/M) * normalVelocityNew(:,iEdge) & + + (1.0_RKIND/M) * normalVelocitySecondStage(:,iEdge) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * normalVelocityCur(:,iEdge) + end do + + layerThicknessForTend(:,:) = layerThicknessSecondStage(:,:) + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + layerThicknessForTend(:,iCell) = (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND/M) * layerThicknessSecondStage(:,iCell) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * layerThicknessCur(:,iCell) + end do + + call mpas_timer_stop('FB_LTS interface prediction') + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=5) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for thickness + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast thickness tendencies") + + call ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocityForTend, layerThicknessForTend, & + 1, 1, 1, 1, 0) + + call mpas_timer_stop("FB_LTS compute fast thickness tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance thickness solution with third stage + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance thickness solution") + + ! Increment interface correction terms + do iRegion = 1,nRegions + do ic = 1, nCellsInLTSRegion(iRegion,2) + iCell = cellsInLTSRegion(iRegion,2,ic) + layerThicknessTendSum3rd(:,iCell) = layerThicknessTendSum3rd(:,iCell) & + + layerThicknessTend(:,iCell) + end do + end do + ! Fine cells adjacent to interface 1 + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) & + + dtFine * layerThicknessTend(:,iCell) + end do + ! Fine in the interior, away from interface 1 + do ic = 1, nCellsInLTSRegion(1,1) + iCell = cellsInLTSRegion(1,1,ic) + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) & + + dtFine * layerThicknessTend(:,iCell) + end do + + call mpas_timer_stop("FB_LTS advance thickness solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Thickness stage 3 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN: Normal velocity stage 3 + ! Compute the third stage of the normal velocity on fine and + ! increment the third stage interface correction terms + + ! Perform forward-backward average of thickness for stage three of + ! FB-RK(3,2): + ! h = weight3*new + (1-2*weight3)*stageTwo + weight3*current + layerThicknessForTend(:,:) = config_fb_weight_3 * layerThicknessNew(:,:) & + + (1.0_RKIND - 2.0_RKIND*config_fb_weight_3) * layerThicknessSecondStage(:,:) & + + config_fb_weight_3 * layerThicknessCur(:,:) + + ! Calculate predicted FB averaged thickness data at + ! intermediate time-level on interface 1: + ! h = weight3*new + (1-2*weight3)*'secondStage' + weight3*'current' + ! = weight3*( ((im+1)/M)*new + (1-(im+1)/M)*current ) + ! + (1-2*weight3)*( (im/M)*new + (1/M)*secondStage + (1-(im+1)/M)*current ) + ! + weight3*( (im/M)*new + (1-im/M)*current ) + call mpas_timer_start('FB_LTS interface prediction') + + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + layerThicknessForTend(:,iCell) = config_fb_weight_3 & + * ( ((REAL(im)+1.0_RKIND)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * layerThicknessCur(:,iCell) ) & + + (1.0_RKIND - 2.0_RKIND*config_fb_weight_3) & + * ( (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND/M) * layerThicknessSecondStage(:,iCell) & + + (1.0_RKIND - (REAL(im)+1.0_RKIND)/M) * layerThicknessCur(:,iCell) ) & + + config_fb_weight_3 & + * ( (REAL(im)/M) * layerThicknessNew(:,iCell) & + + (1.0_RKIND - REAL(im)/M) * layerThicknessCur(:,iCell) ) + end do + + call mpas_timer_stop('FB_LTS interface prediction') + + ! Halo update before tend calculation + call mpas_timer_start("FB_LTS prognostic halo update") + + ! Don't need to update normalVelocityForTend, previously updated + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=5) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Compute fast tendencies for normal velocity + call mpas_timer_start("FB_LTS compute fast tendencies") + call mpas_timer_start("FB_LTS compute fast velocity tendencies") + + call ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocityForTend, layerThicknessForTend, & + 1, 1, 1, 1, 0) + + normalVelocityTend(:,:) = normalVelocityTend(:,:) & + + normalVelocityTendSlow(:,:) + + call mpas_timer_stop("FB_LTS compute fast velocity tendencies") + call mpas_timer_stop("FB_LTS compute fast tendencies") + + ! Advance normal velocity solution with third stage + ! Here, we write into normalVelocityCur, rather than + ! normalVelocityNew, so that the New data is stored + ! in normalVelocityCur to be used at the beginning of the + ! next subcycled time-step + call mpas_timer_start("FB_LTS advance solution") + call mpas_timer_start("FB_LTS advance velocity solution") + + ! Increment interface correction terms + do iRegion = 1,nRegions + do ie = 1, nEdgesInLTSRegion(iRegion,2) + iEdge = edgesInLTSRegion(iRegion,2,ie) + normalVelocityTendSum3rd(:,iEdge) = normalVelocityTendSum3rd(:,iEdge) & + + normalVelocityTend(:,iEdge) + end do + end do + ! Fine cells adjacent to interface 1 + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + normalVelocityCur(:,iEdge) = normalVelocityCur(:,iEdge) & + + dtFine * normalVelocityTend(:,iEdge) + end do + ! Fine in the interior, away from interface 1 + do ie = 1, nEdgesInLTSRegion(1,1) + iEdge = edgesInLTSRegion(1,1,ie) + normalVelocityCur(:,iEdge) = normalVelocityCur(:,iEdge) & + + dtFine * normalVelocityTend(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS advance velocity solution") + call mpas_timer_stop("FB_LTS advance solution") + + ! END: Normal velocity stage 3 + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + ! Copy new solution into cur solution for use at the beginning + ! of the next substep + ! We only do this for layerThickness here because we write + ! into normalVelocityCur rather than normalVelocityNew above + ! for stage 3 of the subcycled normal velocity + call mpas_timer_start("FB_LTS copy soln") + + ! Fine adjacent to interface 1 + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + layerThicknessCur(:,iCell) = layerThicknessNew(:,iCell) + end do + ! Fine in the interior, away from interface 1 + do ic = 1, nCellsInLTSRegion(1,1) + iCell = cellsInLTSRegion(1,1,ic) + layerThicknessCur(:,iCell) = layerThicknessNew(:,iCell) + end do + + call mpas_timer_stop("FB_LTS copy soln") + + end do ! end of fine time-step subcycling loop + + + ! Copy data from normalVelocityCur into normalVelocityNew + ! which currently holds the New data. + call mpas_timer_start("FB_LTS copy soln") + + ! Fine adjacent to interface 1 + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + normalVelocityNew(:,iEdge) = normalVelocityCur(:,iEdge) + end do + ! Fine in the interior, away from interface 1 + do ie = 1, nEdgesInLTSRegion(1,1) + iEdge = edgesInLTSRegion(1,1,ie) + normalVelocityNew(:,iEdge) = normalVelocityCur(:,iEdge) + end do + + call mpas_timer_stop("FB_LTS copy soln") + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! END FINE ADVANCEMENT + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! BEGIN INTERFACE CORRECTION + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + ! Calculate the corrected solution in the interface layers + call mpas_timer_start("FB_LTS interface correction") + + ! Perform the correction on interface 1 and 2 + do iRegion = 1, nRegions + ! Normal velocity correction + do ie = 1, nEdgesInLTSRegion(iRegion,2) + iEdge = edgesInLTSRegion(iRegion,2,ie) + normalVelocityNew(:,iEdge) = normalVelocityCur(:,iEdge) & + + dtFine * normalVelocityTendSum3rd(:,iEdge) + end do + ! Layer thickness correction + do ic = 1, nCellsInLTSRegion(iRegion,2) + iCell = cellsInLTSRegion(iRegion,2,ic) + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) & + + dtFine * layerThicknessTendSum3rd(:,iCell) + end do + end do + + call mpas_timer_stop("FB_LTS interface correction") + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! END INTERFACE CORRECTION + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + ! Final prognostic halo update, is this needed? + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=2) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=2) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + + ! Implicit vmix, DO WE NEED THIS? + call mpas_timer_start("FB_LTS implicit vmix") + if (.not. config_disable_vel_vmix) then + call ocn_diagnostic_solve(dt, statePool, forcingPool, meshPool, & + verticalMeshPool, scratchPool, tracersPool, 2) + call ocn_vmix_implicit(dt, meshPool, statePool, forcingPool, scratchPool, err, 2) + + ! Halo update + call mpas_timer_start("FB_LTS prognostic halo update") + + call mpas_timer_start("FB_LTS velocity halo update") + call mpas_dmpar_field_halo_exch(domain, 'normalVelocity', timeLevel=2) + call mpas_timer_stop("FB_LTS velocity halo update") + + call mpas_timer_start("FB_LTS thickness halo update") + call mpas_dmpar_field_halo_exch(domain, 'layerThickness', timeLevel=2) + call mpas_timer_stop("FB_LTS thickness halo update") + + call mpas_timer_stop("FB_LTS prognostic halo update") + end if + call mpas_timer_stop("FB_LTS implicit vmix") + + call mpas_timer_stop("FB_LTS main loop") + + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! + ! END FB_LTS SCHEME + ! + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + + call mpas_timer_start("FB_LTS cleanup") + + if (config_prescribe_velocity) then + do iEdge = 1, nEdgesAll + normalVelocityNew(:,iEdge) = normalVelocityCur(:,iEdge) + end do + end if + + if (config_prescribe_thickness) then + do iCell = 1, nCellsAll + layerThicknessNew(:,iCell) = layerThicknessCur(:,iCell) + end do + end if + + do iEdge = 1, nEdgesAll + normalTransportVelocity(:,iEdge) = normalVelocityNew(:,iEdge) + end do + + call mpas_reconstruct(meshPool, normalVelocityNew, & + velocityX, velocityY, velocityZ, & + velocityZonal, velocityMeridional, & + includeHalos = .true.) + + call mpas_reconstruct(meshPool, gradSSH, & + gradSSHX, gradSSHY, gradSSHZ, & + gradSSHZonal, gradSSHMeridional, & + includeHalos = .true.) + + do iCell = 1, nCellsAll + surfaceVelocity(indexSurfaceVelocityZonal, iCell) = velocityZonal(1, iCell) + surfaceVelocity(indexSurfaceVelocityMeridional, iCell) = velocityMeridional(1, iCell) + + SSHGradient(indexSSHGradientZonal, iCell) = gradSSHZonal(iCell) + SSHGradient(indexSSHGradientMeridional, iCell) = gradSSHMeridional(iCell) + end do + + call ocn_time_average_coupled_accumulate(statePool, forcingPool, 2) + + do iCell = 1, nCellsAll + surfaceVelocity(indexSurfaceVelocityZonal, iCell) = velocityZonal(1, iCell) + surfaceVelocity(indexSurfaceVelocityMeridional, iCell) = velocityMeridional(1, iCell) + + SSHGradient(indexSSHGradientZonal, iCell) = gradSSHZonal(iCell) + SSHGradient(indexSSHGradientMeridional, iCell) = gradSSHMeridional(iCell) + end do + + ! Update diagnostics + call ocn_diagnostic_solve(dt, statePool, forcingPool, meshPool, & + verticalMeshPool, scratchPool, tracersPool, 2) + + call mpas_pool_destroy_pool(tendSum3rdPool) + call mpas_pool_destroy_pool(tendSlowPool) + + call mpas_pool_remove_subpool(block % structs, 'tend_sum_3rd') + call mpas_pool_remove_subpool(block % structs, 'tend_slow') + + call mpas_timer_stop("FB_LTS cleanup") + + end subroutine ocn_time_integrator_fblts!}}} + + +!||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| +! +! ocn_time_integration_fblts_init +! +!> \brief Initialization for MPAS ocean FB_LTS time integration scheme +!> \author Giacomo Capodaglio +!> \date November 2022 +!> \details +!> This routine computes the LTS arrays +! +!----------------------------------------------------------------------- + + subroutine ocn_time_integration_fblts_init(domain)!{{{ + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + ! Sets the LTS arrays + ! + ! Output: LTS arrays are written + !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! + + implicit none + + !----------------------------------------------------------------- + ! Input/output variables + !----------------------------------------------------------------- + + type (domain_type), intent(inout) :: & + domain !< Input/output: model state + + !----------------------------------------------------------------- + ! Local variables + !----------------------------------------------------------------- + + type (block_type), pointer :: & + block + + type (mpas_pool_type), pointer :: & + LTSPool + + integer, dimension(:), allocatable :: & + isLTSRegionEdgeAssigned + + integer, dimension(:), pointer :: & + LTSRegion + + integer, dimension(:,:), pointer :: & + nCellsInLTSRegion, & + nEdgesInLTSRegion + + integer, dimension(:,:,:), pointer :: & + cellsInLTSRegion, & + edgesInLTSRegion + + integer, dimension(2) :: & + minMaxLTSRegion + + integer :: & + i, iCell, iEdge, iRegion, coarseRegions, & + fineRegions, fineRegionsM1 + + !----------------------------------------------------------------- + ! Begin routine + !----------------------------------------------------------------- + + minMaxLTSRegion(1) = 1 + minMaxLTSRegion(2) = 2 + + block => domain % blocklist + call mpas_pool_get_subpool(block % structs, 'LTS', LTSPool) + + call mpas_pool_get_array(LTSPool, 'LTSRegion', LTSRegion) + call mpas_pool_get_array(LTSPool, 'cellsInLTSRegion', cellsInLTSRegion) + call mpas_pool_get_array(LTSPool, 'nCellsInLTSRegion', nCellsInLTSRegion) + call mpas_pool_get_array(LTSPool, 'edgesInLTSRegion', edgesInLTSRegion) + call mpas_pool_get_array(LTSPool, 'nEdgesInLTSRegion', nEdgesInLTSRegion) + + ! LTS Regions code: + ! 1 = fine + ! 2 = coarse + ! 3 = interface layer 1 + ! 4 = interface layer 2 + ! 5 = fine (to advance when doing 1st, 2nd, 3rd stage on interface) + + nCellsInLTSRegion(:,:) = 0 + nEdgesInLTSRegion(:,:) = 0 + + ! This is a loop to build the lists of elements in the fine, coarse, + ! and interface regions. Only loops up to nCellsOwned because in the + ! time-stepping we only want to advance the cells owned by the MPI process + do iCell = 1, nCellsOwned + do iRegion = 1,2 + if (iRegion == minMaxLTSRegion(iRegion)) then + if(LTSRegion(iCell) == minMaxLTSRegion(iRegion)) then + nCellsInLTSRegion(iRegion,1) = nCellsInLTSRegion(iRegion,1) + 1 + cellsInLTSRegion(iRegion,1,nCellsInLTSRegion(iRegion,1)) = iCell + end if + if(LTSRegion(iCell) == (minMaxLTSRegion(iRegion) + 2) ) then + nCellsInLTSRegion(iRegion,2) = nCellsInLTSRegion(iRegion,2) + 1 + cellsInLTSRegion(iRegion,2,nCellsInLTSRegion(iRegion,2)) = iCell + end if + end if + end do + if (LTSRegion(iCell) == 5) then + nCellsInLTSRegion(1,3) = nCellsInLTSRegion(1,3) + 1 + cellsInLTSRegion(1,3,nCellsInLTSRegion(1,3)) = iCell + end if + end do + + ! Below we fill out the lists for the edges, according to the LTSRegion + ! that have been assigned to the cells. We move from the fine to the + ! coarse (i.e. from the fine to the nearest LTS region in the direction + ! of the coarse). Note that edges shared between cells of different LTS + ! regions are owned by the cell in the LTS region closest to the fine + ! region, see Figure 3 in "Conservative explicit local time-stepping + ! schemes for the shallow water equations" by Hoang et al. (halo edges + ! however are owned by whatever processor they are initially assigned to). + + allocate(isLTSRegionEdgeAssigned(nEdgesOwned)) + isLTSRegionEdgeAssigned(:) = 0 + + do iCell = 1, nCellsInLTSRegion(1,1) + do i = 1, nEdgesOnCell(cellsInLTSRegion(1,1,iCell)) + iEdge = edgesOnCell(i,cellsInLTSRegion(1,1,iCell)) + if (iEdge .le. nEdgesOwned) then + if (isLTSRegionEdgeAssigned(iEdge) == 0) then + nEdgesInLTSRegion(1,1) = nEdgesInLTSRegion(1,1) + 1 + edgesInLTSRegion(1,1, nEdgesInLTSRegion(1,1)) = iEdge + isLTSRegionEdgeAssigned(iEdge) = 1 + end if + end if + end do + end do + + fineRegions = 3 + fineRegionsM1 = 2 + do iRegion = 1, fineRegionsM1 + do iCell = 1, nCellsInLTSRegion(1, fineRegions - iRegion + 1) + do i = 1, nEdgesOnCell(cellsInLTSRegion(1, fineRegions - iRegion + 1, iCell)) + iEdge = edgesOnCell(i,cellsInLTSRegion(1, fineRegions - iRegion + 1, iCell)) + if (iEdge .le. nEdgesOwned) then + if (isLTSRegionEdgeAssigned(iEdge) == 0) then + nEdgesInLTSRegion(1, fineRegions - iRegion + 1) & + = nEdgesInLTSRegion(1, fineRegions - iRegion + 1) + 1 + edgesInLTSRegion(1, fineRegions - iRegion + 1, & + nEdgesInLTSRegion(1, fineRegions - iRegion + 1)) & + = iEdge + isLTSRegionEdgeAssigned(iEdge) = 1 + end if + end if + end do + end do + end do + + coarseRegions = 2 + do iRegion = 1, coarseRegions + do iCell = 1, nCellsInLTSRegion(2, coarseRegions - iRegion + 1) + do i = 1, nEdgesOnCell(cellsInLTSRegion(2,coarseRegions - iRegion + 1,iCell)) + iEdge = edgesOnCell(i,cellsInLTSRegion(2,coarseRegions - iRegion + 1,iCell)) + if (iEdge .le. nEdgesOwned) then + if (isLTSRegionEdgeAssigned(iEdge) == 0) then + nEdgesInLTSRegion(2, coarseRegions - iRegion + 1) & + = nEdgesInLTSRegion(2, coarseRegions - iRegion + 1) + 1 + edgesInLTSRegion(2, coarseRegions - iRegion + 1, & + nEdgesInLTSRegion(2, coarseRegions - iRegion + 1)) & + = iEdge + isLTSRegionEdgeAssigned(iEdge) = 1 + end if + end if + end do + end do + end do + + deallocate(isLTSRegionEdgeAssigned) + + end subroutine ocn_time_integration_fblts_init!}}} + + +!||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| +! +! ocn_lts_thick_tend +! +!> \brief Calculate thickness tendencies for FB_LTS +!> \author Jeremy Lilly +!> \date October 2023 +!> \details +!> This routine calculates the thickness tendency on different +!> LTS regions +! +!----------------------------------------------------------------------- + + subroutine ocn_lts_thick_tend(LTSPool, tendPool, & + normalVelocity, layerThickness, & + computeOnFineInterior, computeOnFineInterfaceAdjacent, & + computeOnInterfaceOne, computeOnInterfaceTwo, & + computeOnCoarse)!{{{ + + !----------------------------------------------------------------- + ! Input variables + !----------------------------------------------------------------- + + integer, intent(in) :: & + computeOnFineInterior, & + computeOnFineInterfaceAdjacent, & + computeOnInterfaceOne, & + computeOnInterfaceTwo, & + computeOnCoarse + + real (kind=RKIND), dimension(:,:), pointer, intent(in) :: & + layerThickness, & + normalVelocity + + type (mpas_pool_type), intent(in) :: & + LTSPool !< Input: LTS data + + !----------------------------------------------------------------- + ! Input/output variables + !----------------------------------------------------------------- + + type (mpas_pool_type), intent(inout) :: & + tendPool !< Input/output: tendency variables + + !----------------------------------------------------------------- + ! Local variables + !----------------------------------------------------------------- + + integer, dimension(:,:), pointer :: & + nCellsInLTSRegion + + integer, dimension(:,:,:), pointer :: & + cellsInLTSRegion + + real (kind=RKIND), dimension(:,:), pointer :: & + layerThicknessTend + + integer :: & + iEdge, cell1, cell2, k, ie, & + ic, i, iCell, kmin, kmax + real (kind=RKIND) :: & + invdcEdge, flux + + !----------------------------------------------------------------- + ! Begin routine + !----------------------------------------------------------------- + + call mpas_pool_get_array(LTSPool, 'cellsInLTSRegion', cellsInLTSRegion) + call mpas_pool_get_array(LTSPool, 'nCellsInLTSRegion', nCellsInLTSRegion) + + call mpas_pool_get_array(tendPool, 'layerThickness', layerThicknessTend) + + ! calculate layerThickEdgeFlux + if (config_thickness_flux_type == 'centered') then + + do iEdge = 1, nEdgesAll + kmin = minLevelEdgeBot(iEdge) + kmax = maxLevelEdgeTop(iEdge) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + do k = 1,nVertLevels + ! initialize layerThicknessEdgeMean to avoid divide by + ! zero and NaN problems. + layerThickEdgeFlux(k,iEdge) = -1.0e34_RKIND + end do + do k = kmin,kmax + ! central differenced + layerThickEdgeFlux(k,iEdge) = 0.5_RKIND * & + ( layerThickness(k,cell1) + & + layerThickness(k,cell2) ) + end do + end do + + else if (config_thickness_flux_type == 'upwind') then + + do iEdge = 1, nEdgesAll + kmin = minLevelEdgeBot(iEdge) + kmax = maxLevelEdgeTop(iEdge) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + do k=1,nVertLevels + ! initialize layerThicknessEdgeFlux to avoid divide by + ! zero and NaN problems. + layerThickEdgeFlux(k,iEdge) = -1.0e34_RKIND + end do + do k = kmin,kmax + if (normalVelocity(k,iEdge) > 0.0_RKIND) then + layerThickEdgeFlux(k,iEdge) = layerThickness(k,cell1) + elseif (normalVelocity(k,iEdge) < 0.0_RKIND) then + layerThickEdgeFlux(k,iEdge) = layerThickness(k,cell2) + else + layerThickEdgeFlux(k,iEdge) = max(layerThickness(k,cell1), & + layerThickness(k,cell2)) + end if + end do + end do + + else + + call mpas_log_write('ERROR: config_thickness_flux_type selected not implemented for FB_LTS', & + messageType=MPAS_LOG_CRIT) + call abort + + end if + + layerThicknessTend(:, :) = 0.0_RKIND + + ! Fine in the interior, away from interface 1 + if (computeOnFineInterior == 1) then + do ic = 1, nCellsInLTSRegion(1,1) + iCell = cellsInLTSRegion(1,1,ic) + do i = 1, nEdgesOnCell(iCell) + iEdge = edgesOnCell(i, iCell) + do k = minLevelEdgeBot(iEdge), maxLevelEdgeTop(iEdge) + flux = normalVelocity(k, iEdge) * dvEdge(iEdge) * layerThickEdgeFlux(k, iEdge) + layerThicknessTend(k, iCell) = layerThicknessTend(k,iCell) & + + edgeSignOnCell(i, iCell) * flux * invAreaCell(iCell) + end do + end do + end do + end if + + ! Fine adjacent to interface 1 + if (computeOnFineInterfaceAdjacent == 1) then + do ic = 1, nCellsInLTSRegion(1,3) + iCell = cellsInLTSRegion(1,3,ic) + do i = 1, nEdgesOnCell(iCell) + iEdge = edgesOnCell(i, iCell) + do k = minLevelEdgeBot(iEdge), maxLevelEdgeTop(iEdge) + flux = normalVelocity(k, iEdge) * dvEdge(iEdge) * layerThickEdgeFlux(k, iEdge) + layerThicknessTend(k, iCell) = layerThicknessTend(k,iCell) & + + edgeSignOnCell(i, iCell) * flux * invAreaCell(iCell) + end do + end do + end do + end if + + ! Interface 1 + if (computeOnInterfaceOne == 1) then + do ic = 1, nCellsInLTSRegion(1,2) + iCell = cellsInLTSRegion(1,2,ic) + do i = 1, nEdgesOnCell(iCell) + iEdge = edgesOnCell(i, iCell) + do k = minLevelEdgeBot(iEdge), maxLevelEdgeTop(iEdge) + flux = normalVelocity(k, iEdge) * dvEdge(iEdge) * layerThickEdgeFlux(k, iEdge) + layerThicknessTend(k, iCell) = layerThicknessTend(k, iCell) & + + edgeSignOnCell(i, iCell) * flux * invAreaCell(iCell) + end do + end do + end do + end if + + ! Interface 2 + if (computeOnInterfaceTwo == 1) then + do ic = 1, nCellsInLTSRegion(2,2) + iCell = cellsInLTSRegion(2,2,ic) + do i = 1, nEdgesOnCell(iCell) + iEdge = edgesOnCell(i, iCell) + do k = minLevelEdgeBot(iEdge), maxLevelEdgeTop(iEdge) + flux = normalVelocity(k, iEdge) * dvEdge(iEdge) * layerThickEdgeFlux(k, iEdge) + layerThicknessTend(k, iCell) = layerThicknessTend(k, iCell) & + + edgeSignOnCell(i, iCell) * flux * invAreaCell(iCell) + end do + end do + end do + end if + + ! Coarse + if (computeOnCoarse == 1) then + do ic = 1, nCellsInLTSRegion(2,1) + iCell = cellsInLTSRegion(2,1,ic) + do i = 1, nEdgesOnCell(iCell) + iEdge = edgesOnCell(i, iCell) + do k = minLevelEdgeBot(iEdge), maxLevelEdgeTop(iEdge) + flux = normalVelocity(k, iEdge) * dvEdge(iEdge) * layerThickEdgeFlux(k, iEdge) + layerThicknessTend(k, iCell) = layerThicknessTend(k,iCell) & + + edgeSignOnCell(i, iCell) * flux * invAreaCell(iCell) + end do + end do + end do + end if + + end subroutine ocn_lts_thick_tend!}}} + + +!||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| +! +! ocn_lts_vel_tend +! +!> \brief Calculate velocity tendencies for FB_LTS +!> \author Jeremy Lilly +!> \date October 2023 +!> \details +!> This routine calculates the velocity tendency on different +!> LTS regions +! +!----------------------------------------------------------------------- + + subroutine ocn_lts_vel_tend(LTSPool, tendPool, & + normalVelocity, layerThickness, & + computeOnFineInterior, computeOnFineInterfaceAdjacent, & + computeOnInterfaceOne, computeOnInterfaceTwo, & + computeOnCoarse)!{{{ + + !----------------------------------------------------------------- + ! Input variables + !----------------------------------------------------------------- + + integer, intent(in) :: & + computeOnFineInterior, & + computeOnFineInterfaceAdjacent, & + computeOnInterfaceOne, & + computeOnInterfaceTwo, & + computeOnCoarse + + real (kind=RKIND), dimension(:,:), pointer, intent(in) :: & + layerThickness, & + normalVelocity + + type (mpas_pool_type), intent(in) :: & + LTSPool !< Input: LTS data + + !----------------------------------------------------------------- + ! Input/output variables + !----------------------------------------------------------------- + + type (mpas_pool_type), intent(inout) :: & + tendPool !< Input/output: tendency variables + + !----------------------------------------------------------------- + ! Local variables + !----------------------------------------------------------------- + + integer, dimension(:,:), pointer :: & + nEdgesInLTSRegion + + integer, dimension(:,:,:), pointer :: & + edgesInLTSRegion + + real (kind=RKIND), dimension(nCellsAll) :: & + ssh + + real (kind=RKIND), dimension(:,:), pointer :: & + normalVelocityTend + + integer :: & + iEdge, cell1, cell2, k, ie, & + ic, i, iCell, kmin, kmax + + real (kind=RKIND) :: & + invdcEdge, betaSelfAttrLoad, flux, ssh_sal_on, tidal_pot_for_on + + !----------------------------------------------------------------- + ! Begin routine + !----------------------------------------------------------------- + + betaSelfAttrLoad = config_self_attraction_and_loading_beta + + call mpas_pool_get_array(LTSPool, 'edgesInLTSRegion', edgesInLTSRegion) + call mpas_pool_get_array(LTSPool, 'nEdgesInLTSRegion', nEdgesInLTSRegion) + + call mpas_pool_get_array(tendPool, 'normalVelocity', normalVelocityTend) + + if (config_use_self_attraction_loading) then + ssh_sal_on = 1.0_RKIND + else + ssh_sal_on = 0.0_RKIND + endif + if (config_use_tidal_potential_forcing) then + tidal_pot_for_on = 1.0_RKIND + else + tidal_pot_for_on = 0.0_RKIND + end if + + ! ssh + do iCell = 1, nCellsAll + k = maxLevelCell(iCell) + zTop(k:nVertLevels,iCell) = -bottomDepth(iCell) + layerThickness(k,iCell) + do k = maxLevelCell(iCell)-1, minLevelCell(iCell), -1 + zTop(k,iCell) = zTop(k+1,iCell) + layerThickness(k,iCell) + end do + ! copy zTop(1,iCell) into sea-surface height array + ssh(iCell) = zTop(minLevelCell(iCell),iCell) + end do + + normalVelocityTend(:,:) = 0.0_RKIND + + ! Fine in the interior, away from interface 1 + if (computeOnFineInterior == 1) then + do ie = 1, nEdgesInLTSRegion(1,1) + iEdge = edgesInLTSRegion(1,1,ie) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + invdcEdge = 1.0_RKIND / dcEdge(iEdge) + kMin = minLevelEdgeBot(iEdge) + kMax = maxLevelEdgeTop(iEdge) + do k=kMin,kMax + normalVelocityTend(k,iEdge) = normalVelocityTend(k,iEdge) & + - edgeMask(k,iEdge) * invdcEdge & + * ( gravity * ( (ssh(cell2) - ssh(cell1)) & + - tidal_pot_for_on * (1.0_RKIND - ssh_sal_on) & + * betaSelfAttrLoad * (ssh(cell2) - ssh(cell1)) ) ) + end do + end do + end if + + ! Fine adjacent to interface 1 + if (computeOnFineInterfaceAdjacent == 1) then + do ie = 1, nEdgesInLTSRegion(1,3) + iEdge = edgesInLTSRegion(1,3,ie) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + invdcEdge = 1.0_RKIND / dcEdge(iEdge) + kMin = minLevelEdgeBot(iEdge) + kMax = maxLevelEdgeTop(iEdge) + do k=kMin,kMax + normalVelocityTend(k,iEdge) = normalVelocityTend(k,iEdge) & + - edgeMask(k,iEdge) * invdcEdge & + * ( gravity * ( (ssh(cell2) - ssh(cell1)) & + - tidal_pot_for_on * (1.0_RKIND - ssh_sal_on) & + * betaSelfAttrLoad * (ssh(cell2) - ssh(cell1)) ) ) + end do + end do + end if + + ! Interface 1 + if (computeOnInterfaceOne == 1) then + do ie = 1, nEdgesInLTSRegion(1,2) + iEdge = edgesInLTSRegion(1,2,ie) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + invdcEdge = 1.0_RKIND / dcEdge(iEdge) + kMin = minLevelEdgeBot(iEdge) + kMax = maxLevelEdgeTop(iEdge) + do k=kMin,kMax + normalVelocityTend(k,iEdge) = normalVelocityTend(k,iEdge) & + - edgeMask(k,iEdge) * invdcEdge & + * ( gravity * ( (ssh(cell2) - ssh(cell1)) & + - tidal_pot_for_on * (1.0_RKIND - ssh_sal_on) & + * betaSelfAttrLoad * (ssh(cell2) - ssh(cell1)) ) ) + end do + end do + end if + + ! Interface 2 + if (computeOnInterfaceTwo == 1) then + do ie = 1, nEdgesInLTSRegion(2,2) + iEdge = edgesInLTSRegion(2,2,ie) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + invdcEdge = 1.0_RKIND / dcEdge(iEdge) + kMin = minLevelEdgeBot(iEdge) + kMax = maxLevelEdgeTop(iEdge) + do k=kMin,kMax + normalVelocityTend(k,iEdge) = normalVelocityTend(k,iEdge) & + - edgeMask(k,iEdge) * invdcEdge & + * ( gravity * ( (ssh(cell2) - ssh(cell1)) & + - tidal_pot_for_on * (1.0_RKIND - ssh_sal_on) & + * betaSelfAttrLoad * (ssh(cell2) - ssh(cell1)) ) ) + end do + end do + end if + + ! Coarse + if (computeOnCoarse == 1) then + do ie = 1, nEdgesInLTSRegion(2,1) + iEdge = edgesInLTSRegion(2,1,ie) + cell1 = cellsOnEdge(1,iEdge) + cell2 = cellsOnEdge(2,iEdge) + invdcEdge = 1.0_RKIND / dcEdge(iEdge) + kMin = minLevelEdgeBot(iEdge) + kMax = maxLevelEdgeTop(iEdge) + do k=kMin,kMax + normalVelocityTend(k,iEdge) = normalVelocityTend(k,iEdge) & + - edgeMask(k,iEdge) * invdcEdge & + * ( gravity * ( (ssh(cell2) - ssh(cell1)) & + - tidal_pot_for_on * (1.0_RKIND - ssh_sal_on) & + * betaSelfAttrLoad * (ssh(cell2) - ssh(cell1)) ) ) + end do + end do + end if + + end subroutine ocn_lts_vel_tend!}}} + + +end module ocn_time_integration_fblts + diff --git a/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F b/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F index 7b8e5154495b..288c79db284d 100644 --- a/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F +++ b/components/mpas-ocean/src/shared/mpas_ocn_diagnostics.F @@ -4485,8 +4485,10 @@ subroutine ocn_diagnostics_init(domain, err)!{{{ ke_cell_flag = 1 endif - if ((trim(config_time_integrator) == 'RK4') .or.(trim(config_time_integrator) == 'LTS') ) then - ! For RK4 or LTS, PV includes f: PV = (eta+f)/h. + if ( (trim(config_time_integrator) == 'RK4') & + .or. (trim(config_time_integrator) == 'LTS') & + .or. (trim(config_time_integrator) == 'FB_LTS') ) then + ! For RK4, LTS, or FB_LTS, PV includes f: PV = (eta+f)/h. fCoef = 1 elseif (trim(config_time_integrator) == 'split_explicit' & .or.trim(config_time_integrator) == 'unsplit_explicit' & diff --git a/components/mpas-ocean/src/shared/mpas_ocn_tendency.F b/components/mpas-ocean/src/shared/mpas_ocn_tendency.F index 2719e1526930..91f182db9993 100644 --- a/components/mpas-ocean/src/shared/mpas_ocn_tendency.F +++ b/components/mpas-ocean/src/shared/mpas_ocn_tendency.F @@ -437,7 +437,9 @@ subroutine ocn_tend_vel(domain, tendPool, statePool, forcingPool, & ! Add tidal potential (if needed) call ocn_compute_tidal_potential_forcing(err) - if ((config_time_integrator == 'RK4') .or. (config_time_integrator =='LTS')) then + if ( (config_time_integrator == 'RK4') & + .or. (config_time_integrator =='LTS') & + .or. (config_time_integrator == 'FB_LTS') ) then ! for split explicit, tidal forcing is added in barotropic subcycles call ocn_vel_tidal_potential_tend(ssh,surfacePressure, tendVel, err) endif diff --git a/components/mpas-ocean/src/shared/mpas_ocn_vel_hadv_coriolis.F b/components/mpas-ocean/src/shared/mpas_ocn_vel_hadv_coriolis.F index 3bc9e3e9284c..8ba260596b31 100644 --- a/components/mpas-ocean/src/shared/mpas_ocn_vel_hadv_coriolis.F +++ b/components/mpas-ocean/src/shared/mpas_ocn_vel_hadv_coriolis.F @@ -359,6 +359,10 @@ subroutine ocn_vel_hadv_coriolis_init(err)!{{{ case ('LTS','lts') ! For LTS, coriolis tendency term includes f: (eta+f)/h. usePlanetVorticity = .true. + + case ('FB_LTS','fb_lts') + ! For FB_LTS, coriolis tendency term includes f: (eta+f)/h. + usePlanetVorticity = .true. case ('split_explicit') ! For split explicit, Coriolis tendency uses eta/h because diff --git a/components/mpas-ocean/src/shared/mpas_ocn_vel_pressure_grad.F b/components/mpas-ocean/src/shared/mpas_ocn_vel_pressure_grad.F index 0615856f6673..8e23913960f5 100644 --- a/components/mpas-ocean/src/shared/mpas_ocn_vel_pressure_grad.F +++ b/components/mpas-ocean/src/shared/mpas_ocn_vel_pressure_grad.F @@ -709,7 +709,8 @@ subroutine ocn_vel_pressure_grad_init(err)!{{{ end select - if (config_time_integrator == 'LTS') then + if ( (config_time_integrator == 'LTS') & + .or. (config_time_integrator == 'FB_LTS') ) then timeIntegratorLTS = .true. else timeIntegratorLTS = .false. diff --git a/components/mpas-ocean/src/shared/mpas_ocn_vel_tidal_potential.F b/components/mpas-ocean/src/shared/mpas_ocn_vel_tidal_potential.F index a13105200ed5..092c52c54d09 100644 --- a/components/mpas-ocean/src/shared/mpas_ocn_vel_tidal_potential.F +++ b/components/mpas-ocean/src/shared/mpas_ocn_vel_tidal_potential.F @@ -503,7 +503,8 @@ subroutine ocn_vel_tidal_potential_init(domain,err)!{{{ call mpas_log_write(' ') end do - if (config_time_integrator == 'LTS') then + if ( (config_time_integrator == 'LTS') & + .or. (config_time_integrator == 'FB_LTS') ) then timeIntegratorLTS = .true. else timeIntegratorLTS = .false. From 4faf908e7ff2f060f23d75ba1ec5ddf58c9ec90a Mon Sep 17 00:00:00 2001 From: Mark Petersen Date: Sun, 3 Mar 2024 18:28:58 -0600 Subject: [PATCH 2/4] add fblts to cmake for E3SM --- components/mpas-ocean/src/ocean.cmake | 1 + 1 file changed, 1 insertion(+) diff --git a/components/mpas-ocean/src/ocean.cmake b/components/mpas-ocean/src/ocean.cmake index 3c0614ee38d5..b353c231df79 100644 --- a/components/mpas-ocean/src/ocean.cmake +++ b/components/mpas-ocean/src/ocean.cmake @@ -32,6 +32,7 @@ list(APPEND RAW_SOURCES core_ocean/mode_forward/mpas_ocn_time_integration_split.F core_ocean/mode_forward/mpas_ocn_time_integration_si.F core_ocean/mode_forward/mpas_ocn_time_integration_lts.F + core_ocean/mode_forward/mpas_ocn_time_integration_fblts.F core_ocean/mode_forward/mpas_ocn_time_integration_split_ab2.F core_ocean/mode_analysis/mpas_ocn_analysis_mode.F From 66d445d586f6d0d02dae0d315688586d87b47b07 Mon Sep 17 00:00:00 2001 From: Mark Petersen Date: Thu, 14 Mar 2024 14:54:31 -0500 Subject: [PATCH 3/4] Add explanation of standalone flags to description --- components/mpas-ocean/src/Registry.xml | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/components/mpas-ocean/src/Registry.xml b/components/mpas-ocean/src/Registry.xml index 68406ed98262..bb399577eee3 100644 --- a/components/mpas-ocean/src/Registry.xml +++ b/components/mpas-ocean/src/Registry.xml @@ -201,8 +201,8 @@ possible_values="Any time stamp in 'YYYY-MM-DD_hh:mm:ss' format. Items can be removed from the left if they are unused." /> Date: Wed, 20 Mar 2024 16:34:07 -0500 Subject: [PATCH 4/4] Update bld files to match Registry --- components/mpas-ocean/bld/build-namelist | 2 +- components/mpas-ocean/bld/build-namelist-section | 2 +- .../bld/namelist_files/namelist_defaults_mpaso.xml | 6 +----- .../bld/namelist_files/namelist_definition_mpaso.xml | 6 +++--- 4 files changed, 6 insertions(+), 10 deletions(-) diff --git a/components/mpas-ocean/bld/build-namelist b/components/mpas-ocean/bld/build-namelist index 0b8d3c782fa7..19418582863e 100755 --- a/components/mpas-ocean/bld/build-namelist +++ b/components/mpas-ocean/bld/build-namelist @@ -557,9 +557,9 @@ add_default($nl, 'config_Redi_constant_kappa'); add_default($nl, 'config_Redi_maximum_slope'); add_default($nl, 'config_Redi_use_slope_taper'); add_default($nl, 'config_Redi_use_surface_taper'); +add_default($nl, 'config_Redi_limit_term1'); add_default($nl, 'config_Redi_use_quasi_monotone_limiter'); add_default($nl, 'config_Redi_quasi_monotone_safety_factor'); -add_default($nl, 'config_Redi_limit_term1'); add_default($nl, 'config_Redi_min_layers_diag_terms'); add_default($nl, 'config_Redi_horizontal_taper'); add_default($nl, 'config_Redi_horizontal_ramp_min'); diff --git a/components/mpas-ocean/bld/build-namelist-section b/components/mpas-ocean/bld/build-namelist-section index 28030392442d..0c834f05cec1 100644 --- a/components/mpas-ocean/bld/build-namelist-section +++ b/components/mpas-ocean/bld/build-namelist-section @@ -96,9 +96,9 @@ add_default($nl, 'config_Redi_constant_kappa'); add_default($nl, 'config_Redi_maximum_slope'); add_default($nl, 'config_Redi_use_slope_taper'); add_default($nl, 'config_Redi_use_surface_taper'); +add_default($nl, 'config_Redi_limit_term1'); add_default($nl, 'config_Redi_use_quasi_monotone_limiter'); add_default($nl, 'config_Redi_quasi_monotone_safety_factor'); -add_default($nl, 'config_Redi_limit_term1'); add_default($nl, 'config_Redi_min_layers_diag_terms'); add_default($nl, 'config_Redi_horizontal_taper'); add_default($nl, 'config_Redi_horizontal_ramp_min'); diff --git a/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml b/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml index 4069eb144cff..7ff1b6744d87 100644 --- a/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml +++ b/components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml @@ -146,15 +146,14 @@ 0.01 .true. .true. +.true. .true. 0.9 -.true. 0 15 'ramp' 'RossbyRadius' 'RossbyRadius' - 'ramp' 20e3 30e3 @@ -180,7 +179,6 @@ 'constant' 'N2_dependent' 'N2_dependent' - 'constant' 900.0 600.0 @@ -198,7 +196,6 @@ 3.0 1.0 1.0 - 3.0 0.13 1000.0 @@ -209,7 +206,6 @@ 'ramp' 'RossbyRadius' 'RossbyRadius' - 'ramp' 20e3 30e3 diff --git a/components/mpas-ocean/bld/namelist_files/namelist_definition_mpaso.xml b/components/mpas-ocean/bld/namelist_files/namelist_definition_mpaso.xml index 01456cd6583a..196d4abf730c 100644 --- a/components/mpas-ocean/bld/namelist_files/namelist_definition_mpaso.xml +++ b/components/mpas-ocean/bld/namelist_files/namelist_definition_mpaso.xml @@ -202,9 +202,9 @@ Default: Defined in namelist_defaults.xml -Time integration method. +Time integration method. These options are only supported in standalone, not E3SM: 'LTS', 'FB_LTS'. -Valid values: 'split_explicit', 'RK4', 'unsplit_explicit', 'split_implicit', 'LTS', 'split_explicit_ab2' +Valid values: 'split_explicit', 'RK4', 'unsplit_explicit', 'split_implicit', 'split_explicit_ab2', 'LTS', 'FB_LTS' Default: Defined in namelist_defaults.xml @@ -2038,7 +2038,7 @@ Default: Defined in namelist_defaults.xml -number of large iterations over stages 1-3 +number of large iterations over stages 1-3; For the split_explicit_ab2 time integrator, this value only affects the first time step when it is not a restart run. For restart runs, this value has no effect on the split_explicit_ab2 time integrator. Valid values: any positive integer, but typically 1, 2, or 3 Default: Defined in namelist_defaults.xml